The present invention generally relates to flexible printed circuits useful at both very high and very low temperatures. More particularly, the present invention relates to flexible printed circuits wherein the substrate is a silicone impregnated fabric such as glass cloth and the printing ink is a silicone composition containing an amount of finely divided metal powder effective for carrying out an augmentation replacement reaction or other process for depositing a conductive metal on said printing ink.
U.S. Pat. No. 3,226,256 to Schneble, incorporated herein by reference, discloses flexible printed circuits prepared by (1) providing an insulating base having surface portions consisting essentially of an adhesive resinous bonding composition having dispersed therein finely divided metal particles of catalytic agent, said resinous bonding composition further comprising a thermosetting resin and a flexible adhesive resin, (2) curing the adhesive resinous bonding composition and (3) treating the resulting base with an electroless metal deposition bath to deposit metal directly on the cured adhesive resinous bonding composition so as to form a conducting pattern.
U.S. Pat. No. 4,404,237 to Eichelberger et al., assigned to the same assignee as the present invention and incorporated herein by reference in its entirety, discloses the formation of an electrical conductor by an augmentation replacement reaction. Briefly, Eichelberger et al. provide a process wherein the desired conductive design is applied to a substrate with an ink composition which comprises a finely divided metal powder, a curable polymer, and a solvent. The curable polymer is at least partially cured and then the resulting ink pattern is contacted with a metal salt solution in which the metal cation is more noble (electropositive) than the metal of the finely divided powder, and the anion forms a salt with the metal of the salt and the powder which is soluble in the solution.